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Cossonus piniphilus Boh. from a parti} - decayed pine log, and at Spokane 

 Falls, W. T., I found Cossonus crenatus Horn under the bark of pine logs 

 and stumps that were still sound. Magdalis Le Contei Horn I have su- 

 spected of depredating in living pine-trees, but am not certain of this. Of 

 Scolytidce I have seen great swarms of Pityophthorus pubipennis Lee. in the 

 branches of newly-felled Live Oaks, and have taken the same or an allied 

 species from sticks of oak that had previously been peeled for tan-bark. 

 P. hamatus Lee. , Tomicus plastographus Lee. and several species of Den 

 droctonus burrow in pine and spruce timber. 



It must not be inferred, however, that because some of these insects 

 burrow in timber-trees that they are destructive to our forests. Many 

 species will never attack a healthy tree but have an acute sense for dis- 

 covering an injured or dying tree or one that has recently fallen. It is 

 the same with many Buprestidae and Cerambycidae. I have taken a 

 dozen Buprestis upon a single pine log, and at night, in a wood-cutters 

 camp, many specimens of Monohammns and Acanthocinus were taken on 

 the piles of cord-wood (pine), and some were shaken from young pines 

 that had been injured by fire, but none were observed on healthy trees. 

 The apple-tree-borer, Chrysobothris femorata, attacks young fruit trees 

 that have been scorched by the sun, but its natural food is the oak for I 

 have seen dozens of them in the branches of a small Live-Oak that had 

 been cut down less than an hour. Xylotrechus nauficus Mann., were 

 also there, in great numbers, some copulating and others ovipositing. 

 Thus also I have observed a swarm of many hnndreds of ' Melanophila con- 

 sputa and M. longipes Say, where a brush fire had scorched some young 

 spruce trees {Abies Doug/asii). M. fulvoguttata also attacks the spruce 

 and M. gentilis the pine, Ergates spiculafus Lee. flourishes equally well 

 in spruce or in pine, but our common Hylotrupes ligncus Fab., I have 

 found only in Redwood*, {Sequoia semperzrirens), and Neocly /us conjum tus 

 Lee. only in the Madrone. 



In all these cases, however, it is only the dying or recently deceased 

 wood that is attacked. Every tree that falls in the forest, every limb 

 that is broken off by the wind, every stick that is cut by the wood-chop- 

 pers axe, is attacked by its own peculiar species. They come from all 

 directions. They swarm about it, and run up and down upon it The 

 sexes will be in copulation; some females will be hunting for suitable 

 crevices in the bark, in which to deposit their eggs; other females will 

 be seen in the act of ovipositing, and last of all, not infrequently, — the 

 parasitic Hymenoptera, in their turn, seeking the eggs of the wood-lovers, 



* Mr. Julich informs me that in the cast, he has found this species confined to 

 red cedar. Ed. 



ENTOMOLOGICA AMERICANA 1 . r > 



